Reverse engineer a DVD?

A client has a DVD. They only need to change 1 word of the audio, but they don't have any of the files used to make the DVD. Is there a way to pull the audio file, make a change, and then replace it back? I don't want to reauthor, just replace assets. Ideas?

Yeah, I don't think so.
All the files inside a DVD are interrelated, and inside the VOB beside the Video and Audio information I guess that there is a bunch of metadata. Even if you can make new VOBs with new audio (thats possible) I guess you would screw the metadata that allows the navigation.
rafael